This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A023313 #28 Aug 31 2024 16:32:53 %S A023313 373,1171,13687,21997,25657,61603,74413,76471,84199,87181,93487, %T A023313 114691,135859,170761,174877,184333,192979,196177,207931,209743, %U A023313 244219,276229,286687,292561,297811,334603,338893,405037,408361,417097,439141,446323 %N A023313 Primes that remain prime through 4 iterations of function f(x) = 5x + 2. %C A023313 Primes p such that 5*p+2, 25*p+12, 125*p+62 and 625*p+312 are also primes. - _Vincenzo Librandi_, Aug 04 2010 %C A023313 Numbers k such that A280720(k) > 3. - _Felix Fröhlich_, Jan 07 2017 %H A023313 John Cerkan, <a href="/A023313/b023313.txt">Table of n, a(n) for n = 1..10000</a> %F A023313 a(n) == 31 or 37 (mod 42). - _John Cerkan_, Oct 07 2016 %t A023313 Select[Range[10^6], Times @@ Boole@ Map[PrimeQ, NestList[5 # + 2 &, #, 4]] == 1 &] (* _Michael De Vlieger_, Jan 09 2017 *) %o A023313 (Magma) [n: n in [1..1000000] | IsPrime(n) and IsPrime(5*n+2) and IsPrime(25*n+12) and IsPrime(125*n+62) and IsPrime(625*n+312)]; // _Vincenzo Librandi_, Aug 04 2010 %Y A023313 Cf. A280720. Subsequence of A023217, A023252, A023283, and A111223. %K A023313 nonn %O A023313 1,1 %A A023313 _David W. Wilson_